1. Field of the Invention
The present invention relates to communication systems, and more particularly, to a method and apparatus that receives variable sized packets in a communication system.
2. Description of the Related Art
Universal Mobile Telecommunication Service (UMTS) systems refer to the 3rd Generation (3G) asynchronous mobile communication system that is based on Global System for Mobile communications (GSM) and General Packet Radio Service (GPRS), and uses a Code Division Multiple Access (CDMA) scheme. The 3rd Generation Partnership Project (3GPP) standardizing UMTS proposes an evolved packet system (EPS), such as a Long Term Evolution (LTE) system. The EPS is designed to perform the transmission and reception of packets at a high rate and high quality.
These conventional communication systems employ an error correction for packets, such as an Automatic Repeat ReQuest (ARQ) and a Hybrid Automatic ReQuest (HARQ). ARQ refers to an error correction technique that attempts the re-transmission of packets to reduce errors and loss of packets in wired communication systems as well as wireless communication systems. According to ARQ, packets before and after re-transmission are equal to each other. HARQ refers to an error correction technique that is advanced from ARQ. In HARQ, packets before and after re-transmission may differ from each other. HARQ reduces the block error rate (BLER) of packets by combining packets before re-transmission with those after re-transmission.
In the conventional communication system, HARQ causes a delay due to re-transmission, and accordingly the convergence rate of packets is decreased. Although BLER can theoretically be reduced to zero as HARQ infinitely repeats re-transmission, the frequency of re-transmissions is practically restricted in such a way to guarantee an appropriate BLER. To this end, a relatively large sized packet is transmitted or re-transmitted in communication systems, thereby reducing the probability of occurrence of a decoding error. If the packet size, however, becomes larger, the communication systems require a large amount of resources during the re-transmission, thereby causing a waste of resources.